By Kantaro Komiya, Hyonhee Shin and Josh Smith
TOKYO/SEOUL (Reuters) -North Korea fired multiple missiles into the sea on Thursday, including a possible failed intercontinental ballistic missile (ICBM), prompting the United States and South Korea to extend air drills that have angered Pyongyang.
An initial Japanese government warning that an apparent ICBM had flown over the country triggered alarms for some residents to seek shelter. Tokyo later said the warning about the missile flying over Japan was incorrect.
The previous day, North fired a daily record 23 missiles, including one that landed off the coast of South Korea for the first time, and drew swift condemnation from Washington, Seoul and Tokyo.
Since Monday, South Korea and the United States have been conducting one of their largest air exercises ever, with hundreds of South Korean and U.S. warplanes, including F-35 fighters, staging around-the-clock simulated missions.
The drills are likely what led North Korea to test a record number of missiles this week, some regional analysts said, but Pyongyang may also be turning up the heat before an expected resumption of nuclear testing for the first time since 2017.
U.S. Defense Secretary Lloyd Austin and his South Korean counterpart Lee Jong-sup held a long-scheduled meeting at the Pentagon on Thursday and agreed in a joint statement to seek new measures to demonstrate the alliance's "determination and capabilities."
At a joint news conference, Austin said he had agreed with Lee to extend the air drills past Friday, when they had been scheduled to end.
"We'll continue to work closely together to develop options to protect the United States and our allies," Austin said.
Lee repeated Seoul's view that North Korea was ready to conduct a nuclear test but said it was difficult to say when it would carry this out.
In response to a question about growing debate in South Korea, Lee said there were no plans to redeploy U.S. tactical nuclear weapons to the peninsula in response to North Korea's activities.
"There is no change in our denuclearisation policy and for now ... we are currently not thinking to deploy tactical nukes on the Korean peninsula," he said.
NO CHANGE IN MILITARY POSTURE
Lee's comments suggested that despite the recent North Korean tests, the U.S. and South Korean alliance is not looking to make major changes to its military posture.
Austin also said the United States did not have any plan to permanently put nuclear-capable assets on the Korean peninsula.
Diplomats said Washington has asked the U.N. Security Council to convene publicly on North Korea on Friday, a request backed by other council members Britain, France, Albania, Ireland and Norway.
North Korea has long been banned from conducting nuclear tests and ballistic missile launches by the Security Council, which has strengthened sanctions on Pyongyang over the years to try and cut off funding for those programs.
However, in recent years the 15-member council has been split on how to deal with North Korea and in May, China and Russia vetoed a U.S.-led push to impose more U.N. sanctions in response to North Korean missile launches.
On Thursday, Pak Jong Chon, secretary of the Central Committee of North Korea's ruling Workers' Party, said Washington and Seoul had made a very dangerous decision by extending the drills, and were "shoving" the situation out of control.
"The United States and South Korea will find that they have made a terrible mistake that cannot be reversed," said Pak.
The United States said that among the missiles fired on Thursday was an ICBM, which are North Korea's longest-range weapons and are designed to carry a nuclear warhead to the other side of the planet.
North Korea also launched as many as five short-range ballistic missiles.
South Korean officials believe the ICBM failed in flight, Yonhap news agency reported, without elaborating. The South Korean and Japanese defence ministries declined to confirm the possible failure.
Japanese Defence Minister Yasukazu Hamada said the government lost track of the ICBM over the Sea of Japan, prompting it to correct its announcement that it had flown over the country.
Former Japan Maritime Self Defense Force fleet commander Yoji Koda said the loss of radar tracking on the projectile pointed to a failed launch.
"It means at some point in the flight path there was some problem for the missile and it actually came apart," he said.
North Korea has had several failed ICBM tests this year, according to South Korean and U.S. officials.
South Korean Vice Foreign Minister Cho Hyun-dong and U.S. Deputy Secretary of State Wendy Sherman condemned North Korea's missile launches as "deplorable and immoral" during a phone call on Thursday, Seoul's foreign ministry said.
Japanese Prime Minister Fumio Kishida said North Korea's "repeated missile launches are an outrage and absolutely cannot be forgiven".
U.S. State Department spokesman Ned Price said the ICBM launch demonstrated the threat from Pyongyang's unlawful weapons programmes.
Chinese foreign ministry spokesperson Zhao Lijian avoided commenting directly on the launches , instead repeating a standard line from Beijing that it hoped all parties could peacefully resolve issues through dialogue.
(Reporting by Kantoro Komiya, Tim Kelly, Chang-Ran Kim and David Dolan in TOKYO, Hyonhee Shin and Josh Smith in SEOUL, Eduardo Baptista in BEIJING, Michelle Nichols at the UNITED NATIONS and David Brunnstrom in WASHINGTON; Writing by Josh Smith; Editing by Kim Coghill, Alexandra Hudson, Mark Heinrich and Grant McCool)